package com.cyj.comment.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * @ClassName RedisIdWorker
 * @Description 基于redis的id生成器
 * @Author chixiaowai
 * @Date 2023/4/7 21:45
 * @Version 1.0
 */
@Component
public class RedisIdWorker {
    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    /**
     * 序列号长度
     */
    private static final int COUNT_BITS = 32;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    public long nextID(String keyPrefix){
        //1、生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = nowSecond - BEGIN_TIMESTAMP;
        //2、生成序列号
        //2.1、获取当前日期,精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //2.2、自增
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);
        //3、将时间戳和序列号拼接
        return timeStamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println(second);
    }
}
